The subject matter disclosed herein relates to X-ray tubes, and in particular, to X-ray cathode systems and methods of manufacturing X-ray cathodes.
X-ray tubes typically include an electron source, such as a cathode, that releases electrons at high acceleration. Some of the released electrons may impact a target anode. The collision of the electrons with the target anode produces X-rays, which may be used in a variety of medical devices such as computed tomography (CT) imaging systems, X-ray scanners, and so forth. In thermionic cathode systems, a filament is included that may be induced to release electrons through the thermionic effect, i.e. in response to being heated. However, the distance between the cathode and the anode must be kept short so as to allow for proper electron bombardment. Further, thermionic X-ray cathodes typically emit electrons throughout the entirety of the surface of the filament. Accordingly, it is very difficult to focus all electrons into a small focal spot.